<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    let m = prompt("请输入：")
    m = parseInt(m);
    switch (m) {
        case 1:
            alert("星期一")
            break
        case 2:
            alert("星期二")
            break
        case 3:
            alert("星期三")
            break
        case 4:
            alert("星期四")
            break
        case 5:
            alert("星期5")
            break
        case 6:
            alert("星期六")
            break
        case 7:
            alert("星期7")
            break
        default:
            alert("输入错误")
            break
    }

</script>

</html>